In the prior art singlet oxygen is already used in the pharmaceutical field, for example in photodynamic therapy. For this purpose, before the therapy a photosensitising substance, a so-called sensitiser, is administered which accumulates in higher concentration in the tumour tissue than in normal tissue. The sensitiser is excited by irradiation with light, and in the presence of oxygen it can generate singlet oxygen which causes lethal oxidative damage, damaging membrane lipids for example. Because of the interaction of sensitiser and irradiation due to (laser) light the range of applications of the PDT is restricted because of the limited depth of penetration of the therapeutic light. Therefore PDT is preferred for local treatment of superficial carcinomas on the skin or endoscopically accessible hollow organs.
Therefore the object of the present invention is to use the release of singlet oxygen (1O2) to kill specific biological objects, in particular cells in tumour therapy, such as for example cancer cells, or resistant germs for example by antimicrobial treatment). Because of the short lifespan of singlet oxygen the technically most important problem is that the distance between the production site and the site of action (that is to say the target region in the interior or on the surface of the cell) must be kept very small. This distance depends upon the particular medium in which the singlet oxygen should diffuse into the target region and will generally be less than 1 μ.